diff --git a/server/channels/app/platform/config.go b/server/channels/app/platform/config.go
index 235e077c1d..d852d6b35c 100644
--- a/server/channels/app/platform/config.go
+++ b/server/channels/app/platform/config.go
@@ -369,12 +369,7 @@ func (ps *PlatformService) IsFirstUserAccount() bool {
 }
 
 func (ps *PlatformService) MaxPostSize() int {
-	maxPostSize := ps.Store.Post().GetMaxPostSize()
-	if maxPostSize == 0 {
-		return model.PostMessageMaxRunesV1
-	}
-
-	return maxPostSize
+	return ps.Store.Post().GetMaxPostSize()
 }
 
 func (ps *PlatformService) isUpgradedFromTE() bool {
diff --git a/server/channels/app/post_test.go b/server/channels/app/post_test.go
index bd6d867e4a..3f12000da2 100644
--- a/server/channels/app/post_test.go
+++ b/server/channels/app/post_test.go
@@ -19,9 +19,7 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/plugin/plugintest/mock"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
-	"github.com/mattermost/mattermost/server/v8/channels/app/platform"
 	"github.com/mattermost/mattermost/server/v8/channels/store"
-	"github.com/mattermost/mattermost/server/v8/channels/store/storetest"
 	storemocks "github.com/mattermost/mattermost/server/v8/channels/store/storetest/mocks"
 	"github.com/mattermost/mattermost/server/v8/channels/testlib"
 	eMocks "github.com/mattermost/mattermost/server/v8/einterfaces/mocks"
@@ -731,53 +729,6 @@ func TestImageProxy(t *testing.T) {
 	}
 }
 
-func TestMaxPostSize(t *testing.T) {
-	t.Parallel()
-
-	testCases := []struct {
-		Description         string
-		StoreMaxPostSize    int
-		ExpectedMaxPostSize int
-	}{
-		{
-			"Max post size less than model.model.POST_MESSAGE_MAX_RUNES_V1 ",
-			0,
-			model.PostMessageMaxRunesV1,
-		},
-		{
-			"4000 rune limit",
-			4000,
-			4000,
-		},
-		{
-			"16383 rune limit",
-			16383,
-			16383,
-		},
-	}
-
-	for _, testCase := range testCases {
-		t.Run(testCase.Description, func(t *testing.T) {
-			mockStore := &storetest.Store{}
-			defer mockStore.AssertExpectations(t)
-
-			mockStore.PostStore.On("GetMaxPostSize").Return(testCase.StoreMaxPostSize)
-
-			app := App{
-				ch: &Channels{
-					srv: &Server{
-						platform: &platform.PlatformService{
-							Store: mockStore,
-						},
-					},
-				},
-			}
-
-			assert.Equal(t, testCase.ExpectedMaxPostSize, app.MaxPostSize())
-		})
-	}
-}
-
 func TestDeletePostWithFileAttachments(t *testing.T) {
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
diff --git a/server/channels/store/sqlstore/post_store.go b/server/channels/store/sqlstore/post_store.go
index d800fcc5a1..d1af5c846f 100644
--- a/server/channels/store/sqlstore/post_store.go
+++ b/server/channels/store/sqlstore/post_store.go
@@ -2619,17 +2619,14 @@ func (s *SqlPostStore) determineMaxPostSize() int {
 			mlog.Warn("Unable to determine the maximum supported post size", mlog.Err(err))
 		}
 	} else {
-		mlog.Warn("No implementation found to determine the maximum supported post size")
+		mlog.Error("No implementation found to determine the maximum supported post size")
 	}
 
 	// Assume a worst-case representation of four bytes per rune.
 	maxPostSize := int(maxPostSizeBytes) / 4
 
-	// To maintain backwards compatibility, don't yield a maximum post
-	// size smaller than the previous limit, even though it wasn't
-	// actually possible to store 4000 runes in all cases.
-	if maxPostSize < model.PostMessageMaxRunesV1 {
-		maxPostSize = model.PostMessageMaxRunesV1
+	if maxPostSize < model.PostMessageMaxRunesV2 {
+		maxPostSize = model.PostMessageMaxRunesV2
 	}
 
 	mlog.Info("Post.Message has size restrictions", mlog.Int("max_characters", maxPostSize), mlog.Int("max_bytes", maxPostSizeBytes))
diff --git a/server/channels/store/storetest/post_store.go b/server/channels/store/storetest/post_store.go
index 0aa40a962a..2e74d60747 100644
--- a/server/channels/store/storetest/post_store.go
+++ b/server/channels/store/storetest/post_store.go
@@ -4314,8 +4314,7 @@ func testPostStoreGetOldest(t *testing.T, rctx request.CTX, ss store.Store) {
 	assert.EqualValues(t, o2.Id, r1.Id)
 }
 
-func testGetMaxPostSize(t *testing.T, rctx request.CTX, ss store.Store) {
-	assert.Equal(t, model.PostMessageMaxRunesV2, ss.Post().GetMaxPostSize())
+func testGetMaxPostSize(t *testing.T, _ request.CTX, ss store.Store) {
 	assert.Equal(t, model.PostMessageMaxRunesV2, ss.Post().GetMaxPostSize())
 }